Download full text in PDF

Tijjani MB, Ibrahim AM. Evaluating the safety of genetically modified crops: Findings from toxicological meta-research. Bìol Tvarin. 2025; 27 (3): 27–41. DOI: 10.15407/animbiol27.03.027.
https://doi.org/10.15407/animbiol27.03.027
Received 23.04.2025 ▪ Revision 04.08.2025 ▪ Accepted 18.08.2025 ▪ Published online 22.10.2025

---

Evaluating the safety of genetically modified crops: Findings from toxicological meta-research

Mohammed Bashir Tijjani¹, Adamkolo Mohammed Ibrahim²
This email address is being protected from spambots. You need JavaScript enabled to view it., This email address is being protected from spambots. You need JavaScript enabled to view it.

¹University of Maiduguri, Faculty of Veterinary Medicine, Department of Veterinary Pharmacology and Toxicology,
1069 Bama Road, Maiduguri, Borno State, 600104, Nigeria

²University of Maiduguri, Faculty of Communication and Media Studies, Department of Mass Communication,
1069 Bama Road, Maiduguri, Borno State, 600104, Nigeria

---

This meta-analysis examined the safety of genetically modified (GM) crops by collating findings from controlled animal feeding trials and human observational studies published between 2017 and 2025. The investigation critically assessed acute and chronic toxicity, allergenicity, metabolic disturbances and carcinogenic endpoints, focusing on research from Nigeria, Africa and Western regions (Europe and the USA). Advanced statistical methods, including random-effects modelling, subgroup analyses and meta-regression, were employed to quantify heterogeneity and evaluate the robustness of the evidence. The findings are presented in percentage terms to facilitate a clear summary of the safety profile of GM crops. The analysis indicates that genetically modified foods are not acutely toxic while some studies reported minor metabolic and immunological changes on chronic or prolonged exposure. Discrepancies in chronic toxicity findings were largely due to variations in experimental model, study design and sample size. Therefore, overall evidence supports the general safety of GM crops under current testing protocols; however, some uncertainties persist regarding long-term effects. Hence, the paper concluded that safety depends on the type of modifications made. Insect-resistant and pesticide-tolerant modifications are more associated with safety concerns than any other type, like biofortified modification.

Key words: genetically modified crops, toxicological safety, meta-research, crop-vigilance, risk assessment

---

1. Adeyeye SAO, Idowu-Adebayo F. Genetically modified and biofortified crops and food security in developing countries: a review. Nutr Food Sci. 2019; 49 (5): 978–986. DOI: 10.1108/NFS-12-2018-0335.
2. Akinbo O, Obukosia S, Ouedraogo J, Sinebo W, Savadogo M, Timpo S, Mbabazi R, Maredia K, Makinde D, Ambali A. Commercial release of genetically modified crops in Africa: Interface between biosafety regulatory systems and varietal release systems. Front Plant Sci. 2021; 12: 605937. DOI: 10.3389/fpls.2021.605937.
3. Amedu J, Adediji A, Miracle N, Anthony A, Adeyemi P, Ahmed R, Atsumbe S, Costly M, Majekodunmi A, Balogun O, Akinpelu O, Borgbara K, Olufowobi O, Tahir HJ, Aroworamimo L, Asagbra A. What’s in (y)our food? — Occurrence of GM-containing foods on the Nigerian market and compliance with national regulations. J Genet Eng Biotechnol. 2025; 23 (2): 100481. DOI: 10.1016/j.jgeb.2025.100481.
4. Azadi H, Taheri F, Ghazali S, Moghaddam SM, Siamian N, Goli I, Choobchian S, Pour M, Özgüven AI, Janečková K, Sklenička P, Witlox F. Genetically modified crops in developing countries: saviour or traitor? J Cleaner Prod. 2022; 371: 133296. DOI: 10.1016/j.jclepro.2022.133296.
5. Bakshi A. Potential adverse health effects of genetically modified crops. J Toxicol Environ Health B. 2003; 6 (3): 211–225. DOI: 10.1080/10937400306469.
6. Benevenuto RF, Venter HJ, Zanatta CB, Nodari RO, Agapito-Tenfen SZ. Alterations in genetically modified crops assessed by omics studies: Systematic review and meta-analysis. Trends Food Sci Technol. 2022; 120: 325–337. DOI: 10.1016/j.tifs.2022.01.002.
7. Bischoff NS, Bussi MR, Van Breda SG, Jolani S, Sijm DTHM, de Kok TM, Briedé JJ. Food-grade titanium dioxide exposure between age groups and in global regions: A systematic review and meta-analysis. Crit Rev Food Sci Nutr. 2025: 1–11. DOI: 10.1080/10408398.2025.2467823.
8. Brune P, Chakravarthy S, Graser GA, Mathesius CA, McClain S, Petrick JS, Sauve-Ciencewicki A, Schafer B, Silvanovich A, Brink K, Burgin K, Bushey D, Cheever ML, Edrington T, Fu H, Habex V, Herman RA, Islamovic E, Lipscomb EA, Motyka S, Privalle L, Ranjan R, Roper J, Song P, Tilton G, Zhang J, Waters S, Ramos A, Hendrickson Culler A, Hunst P, Gast R, Mahadeo D, Goodwin L. Core and supplementary studies to assess the safety of genetically modified (GM) plants used for food and feed. J Reg Sci. 2021; 9 (1): 45–60. DOI: 10.21423/JRS-V09I1BRUNE.
9. Caradus JR. Intended and unintended consequences of genetically modified crops — myth, fact and/or manageable outcomes? New Zealand J Agric Res. 2023; 66 (6): 519–619. DOI: 10.1080/00288233.2022.2141273.
10. Catacora-Vargas G, Binimelis R, Myhr AI, Wynne B. Socio-economic research on genetically modified crops: A study of the literature. Agric Human Values. 2018; 35: 489–513. DOI: 10.1007/s10460-017-9842-4.
11. Dadgarnejad M, Kouser S, Moslemi M. Genetically modified foods: Promises, challenges and safety assessments. Appl Food Biotechnol. 2017; 4 (4): 193–202. DOI: 10.22037/afb.v4i4.17244.
12. Dang C, Wang F, Lu Z, Ye G. Application of meta-analysis in the safety assessments of transgenic crops. Chin J Biol Control. 2020; 36 (1): 17–23. DOI: 10.16409/j.cnki.2095-039x.2019.05.012.
13. Dowd-Uribe B, Rock JS, Spreadbury T, Chiril P, Uminsky D. Bridging the gap? Public-private partnerships and genetically modified crop development for smallholder farmers in Africa. Plants People Planet. 2024; 6 (2): 437–451. DOI: 10.1002/ppp3.10453.
14. Ebegba R, Bello S, Onwude J. Status of Nigeria’s biosafety regulation. In: Uzochukwu S, Esiobu ND, Okoli AS, Nwoba EG, Christpeace EN, Adetunji CO, Ibrahim ABT, Ubi BE (eds). Biosafety and bioethics in biotechnology. CRC Press; 2022: 1–18. DOI: 10.1201/9781003179177.
15. EFSA Panel on Contaminants in the Food Chain (CONTAM), Knutsen HK, Alexander J, Barregård L, Bignami M, Brüschweiler B, Ceccatelli S, Cottrill B, Dinovi M, Edler L, Grasl-Kraupp B, Hoogenboom LR, Nebbia CS, Oswald IP, Petersen A, Rose M, Roudot AC, Schwerdtle T, Vleminckx C, Vollmer G, Wallace H, Lundebye AK, Metzler M, Colombo P, Hogstrand C. Assessment of a decontamination process for dioxins and PCBs from fish meal by replacement of fish oil. EFSA J. 2018; 16 (2): e05174. DOI: 10.2903/j.efsa.2018.5174.
16. EFSA Panel on Contaminants in the Food Chain (CONTAM), Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl-Kraupp B, Hoogenboom LR, Leblanc JC, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Vleminckx C, Wallace H, Rose M, Cottrill B, Lundebye AK, Metzler M, Christodoulidou A, Hogstrand C. Decontamination process for dioxins and dioxin-like PCBs from fish oil and vegetable oils and fats by a physical process with activated carbon. EFSA J. 2022; 20 (9): e07524. DOI: 10.2903/j.efsa.2022.7524.
17. Elwell DA. Industry-influenced evidence: bias, conflict, and manipulation in scientific evidence. BCL Rev. 2020; 61 (6): 2155–2190. Available at: https://bclawreview.bc.edu/articles/214
18. Gbadegesin LA, Ayeni EA, Tettey CK, Uyanga VA, Aluko OO, Ahiakpa JK, Okoye CO, Mbadianya JI, Adekoya MA, Aminu RO, Oyawole FP, Odufuwa P. GMOs in Africa: status, adoption and public acceptance. Food Control. 2022; 141: 109193. DOI: 10.1016/j.foodcont.2022.109193.
19. Gbashi S, Adebo O, Adebiyi JA, Targuma S, Tebele S, Areo OM, Olopade B, Odukoya JO, Njobeh P. Food safety, food security and genetically modified organisms in Africa: A current perspective. Biotechnol Genet Eng Rev. 2021; 37 (1): 30–63. DOI: 10.1080/02648725.2021.1940735.
20. Glevitzky M, Glevitzky I, Mucea-Ștef P, Popa M, Dumitrel GA, Vică ML. Integrated risk framework (IRF) — interconnection of the Ishikawa diagram with the enhanced HACCP system in risk assessment for the sustainable food industry. Sustainability. 2025; 17 (2): 536. DOI: 10.3390/su17020536.
21. Glover B, Akinbo O, Savadogo M, Timpo S, Lemgo G, Sinebo W, Akile S, Obukosia S, Ouedraogo J, Ndomondo-Sigonda M, Koch M, Makinde Diran, Ambali A. Strengthening regulatory capacity for gene drives in Africa: leveraging NEPAD’s experience in establishing regulatory systems for medicines and GM crops in Africa. BMC Proc. 2018; 12 (8): 11. DOI: 10.1186/s12919-018-0108-y.
22. Hermans E, Toelen J, Ventrella D, De Schaepdrijver L, Turner K, Croubels S, Devreese M. Application of preclinical juvenile animal models. In: Gasthuys E, Allegaert K, Dossche L, Turner M (eds). Essentials of translational pediatric drug development: from past needs to future opportunities. Academic Press; 2024: 189–212. DOI: 10.1016/B978-0-323-88459-4.00009-2.
23. Huang K. Safety assessment of genetically modified foods. Springer, 2017. DOI: 10.1007/978-981-10-3488-6.
24. Ikpeama OJ, Ibeh IN, Emokpae MA, Ikpeama CA, Ikpeama CJ, Okafor PA, Igbineweka OO, Ikpeama EA, Ofuenyi J, Ogbonna CO, Ogwuegbu JU. Evaluation of some herbicide content in agricultural produce in Sokoto metropolis. Int J Innov Sci Res Rev. 2019; 1 (5): 44–51. Available at: https://journalijisr.com/sites/default/files/issues-pdf/IJISRR-120.pdf
25. Josephs JJ. Perceptions of validity: how knowledge is created, transformed and used in bio-agricultural technology safety testing for the development of government policies and regulations. Dissertation. Nova Southeastern University; 2017. Available at: https://core.ac.uk/outputs/84414244
26. Kedisso EG, Maredia K, Guenthner J, Koch M. Commercialization of genetically modified crops in Africa: opportunities and challenges. Afr J Biotechnol. 2022; 21 (5): 188–197. DOI: 10.5897/AJB2021.17434.
27. Kolapo A, Kolapo AJ. Welfare and productivity impact of adoption of biofortified cassava by smallholder farmers in Nigeria. Cogent Food Agric. 2021; 7 (1): 1886662. DOI: 10.1080/23311932.2021.1886662.
28. Krogh PH, Kostov K, Damgaard CF. The effect of Bt crops on soil invertebrates: a systematic review and quantitative meta-analysis. Transgenic Res. 2020; 29: 487–498. DOI: 10.1007/s11248-020-00213-y.
29. Liaqat A, Salisu IB, Bakhsh A, Ali Q, Imran A, Ali MA, Farooq AM, Rao AQ, Shahid AA. A sub chronic feeding study of dual toxin insect resistant transgenic maize (CEMB 413) on Wistar rats. PLoS One. 2023; 18 (8): e0285090. DOI: 10.1371/journal.pone.0285090.
30. Lozada-Martinez ID, Hernandez-Paz DA, Fiorillo-Moreno O, Picón-Jaimes YA, Bermúdez V. Meta-research in biomedical investigation: Gaps and opportunities based on meta-research publications and global indicators in health, science, and human development. Publications. 2025; 13 (1): 7. DOI: 10.3390/publications13010007.
31. Marsteller N, Bøgh KL, Goodman RE, Epstein MM. A review of animal models used to evaluate potential allergenicity of genetically modified organisms (GMOs). Drug Discov Today Dis Models. 2015; 17–18: 81–88. DOI: 10.1016/j.ddmod.2016.11.001.
32. Mmbando GS. The adoption of genetically modified crops in Africa: The public’s current perception, the regulatory obstacles, and ethical challenges. GM Crops Food. 2024; 15 (1): 185–199. DOI: 10.1080/21645698.2024.2345401.
33. Mmbando GS. The legal aspect of the current use of genetically modified organisms in Kenya, Tanzania, and Uganda. GM Crops Food. 2023; 14 (1): 1–12. DOI: 10.1080/21645698.2023.2208999.
34. Modonesi C, Gusmeroli F. Evidence-based science or science-based evidence? The GM crops between false myths and ecological systems. Organisms J Biol Sci. 2018; 2 (1): 63–72. DOI: 10.13133/2532-5876_3.13.
35. Moresis A, Restivo L, Bromilow S, Flik G, Rosati G, Scorrano F, Tsoory M, O’Connor EC, Gaburro S, Bannach-Brown A. A minimal metadata set (MNMS) to repurpose nonclinical in vivo data for biomedical research. Lab Anim. 2024; 53 (3): 67–79. DOI: 10.1038/s41684-024-01335-0.
36. Munoz-Muriedas J. Large scale meta-analysis of preclinical toxicity data for target characterisation and hypotheses generation. PLoS One. 2021; 16 (6): e0252533. DOI: 10.1371/journal.pone.0252533.
37. Murayi JA, Evenson E, Britton C, Gehred A, Goday PS. Clinical effects of pediatric commercial food-based formulas: A systematic review. J Pediatr Gastroenterol Nutr. 2025; 80 (3): 501–509. DOI: 10.1002/jpn3.12450.
38. Nang’Ayo F, Simiyu-Wafukho S, Oikeh SO. Regulatory challenges for GM crops in developing economies: The African experience. Transgen Res. 2024; 23: 1049–1055. DOI: 10.1007/s11248-014-9805-0.
39. Ogwu MC, Thompson OP, Kosoe EA, Mumuni E, Akolgo-Azupogo H, Obahiagbon EG, Izah SC, Imarhiagbe O. Factors driving the acceptance of genetically modified food crops in Ghana. Food Saf Health. 2024; 2 (1): 158–168. DOI: 10.1002/fsh3.12031.
40. Oladipo OH, Ibrahim RR, Adeboye SE, Kuiper H. Readiness of the Nigerian public for the introduction of genetically modified crops into the food market. Afr J Biotechnol. 2020 ;19 (7): 426–438. DOI: 10.5897/AJB2020.17136.
41. Ongu I, Olayide P, Alexandersson E, Zawedde BM, Eriksson D. Biosafety regulatory frameworks in Kenya, Nigeria, Uganda and Sweden and their potential impact on international R&D collaborations. GM Crops Food. 2023; 14 (1): 1–17. DOI: 10.1080/21645698.2023.2194221.
42. Patial R, Sobti RC. Exploring the impact of meta-analysis in scientific research: A review. Medinformatics. 2024; 00 (00): 1–11. DOI: 10.47852/bonviewMEDIN42022447.
43. Rao A. Industry-funded research and bias in food science. Quant Mark Econ. 2022; 20 (1): 39–67. DOI: 10.1007/s11129-021-09244-z.
44. Sandhu R, Chaudhary N, Shams R, Dash KK. Genetically modified crops and sustainable development: Navigating challenges and opportunities. Food Sci Biotechnol. 2025; 34 (2): 307–323. DOI: 10.1007/s10068-024-01669-y.
45. Schiemann J, Dietz-Pfeilstetter A, Hartung F, Kohl C, Romeis J, Sprink T. Risk assessment and regulation of plants modified by modern biotechniques: Current status and future challenges. Ann Rev Plant Biol. 2019; 70 (1): 699–726. DOI: 10.1146/annurev-arplant-050718-100025.
46. Sendhil R, Nyika J, Yadav S, Mackolil J, Rama Prashat G, Workie E, Ragupathy R, Ramasundaram P. Genetically modified foods: Bibliometric analysis on consumer perception and preference. GM Crops Food. 2022; 13 (1): 65–85. DOI: 10.1080/21645698.2022.2038525.
47. Shen C, Yin XC, Jiao BY, Li J, Jia P, Zhang XW, Cheng XH, Ren JX, Lan HD, Hou WB, Fang M, Li X, Fei YT, Robinson N, Liu JP. Evaluation of adverse effects/events of genetically modified food consumption: A systematic review of animal and human studies. Environ Sci Eur. 2022; 34: 8. DOI: 10.1186/s12302-021-00578-9.
48. Smyth SJ. Genetically modified crops, regulatory delays, and international trade. Food Energy Secur. 2017; 6 (2): 78–86. DOI: 10.1002/fes3.100.
49. Sreelatha HV, Patel S, Nagarajan P. The key concepts of animal models. In: Sreelatha HV, Patel S, Nagarajan P (eds). Animal models in research: principles and practice. Springer; 2024: 3–16. DOI: 10.1007/978-981-97-0048-6_1.
50. Then C, Miyazaki J, Bauer-Panskus A. Deficiencies in the risk assessment of genetically engineered Bt cowpea approved for cultivation in Nigeria: A critical review. Plants. 2022; 11 (3): 380. DOI: 10.3390/plants11030380.
51. Yahaya U, Suleiman RA, Hussaini Y, Hamidu ST, Odey BO, Adaaja BO. Environmental risk and biosafety of genetically modified plants. Niger J Biotechnol. 2024; 41 (2): 104–108. DOI: 10.4314/njb.v41i2.9.